Worked on front end for years. Rarely ever hear people talking about performance issues. I was among the very few people who knew how to use the dev tools to investigate memory leak or heard of memlab.

Either the team I worked at was horrible, or you are from Google/Meta/Walmart where either everyone is smart or frondend performance is directly related to $$.

There are some really fast tools out there for compiling FE these days, and that's probably to what they refer. Testing is still a slog.

Uh, I've worked for a few years as a frontend dev, as in literal frontend dev - at that job my responsibility started at consuming and ended at feeding backend APIs, essentially.

From that I completely agree with your statement - however, you're not addressing the point he makes which kinda makes your statement completely unrelated to his point

99.99% of all performance issues in the frontend are caused by devs doing dumb shit at this point

The frameworks performance benefits are not going to meaningfully impact this issue anymore, hence no matter how performant yours is, that's still going to be their primary complaint across almost all complex rwcs

And the other issue is that we've decided that complex transpiling is the way to go in the frontend (typescript) - without that, all built time issues would magically go away too. But I guess that's another story.

It was a different story back when eg meteorjs was the default, but nowadays they're all fast enough to not be the source of the performance issues